NISCAIR Online Periodicals Repository Collection: IJEB Vol.48(01) [January 2010]

Screening and partial immunochemical characterization of sulfite oxidase from plant source

Title: Screening and partial immunochemical characterization of sulfite oxidase from plant source

Authors: Ahmad, Ausaf; Ahmad, Sarfraz

Abstract: Sulfite oxidase [SO; EC 1.8.3.1] catalyses the physiologically vital oxidation of sulfite to sulfate, the terminal reaction in degradation of sulfur containing amino acids, cysteine and methionine. Sulfite oxidase from vertebrate sources is among the best studied molybdenum enzymes. Existence of SO in plants has been established recently by identification of a cDNA from Arabidopsis thaliana encoding a functional SO. The present study was undertaken to identify herbaceous and woody plants (viz., Azardirachta indica L., Cassia fistula L., Saraca indica L., Spinacea oleracea L., and Syzyzium cumini L.), a relatively less explored source, having significant SO activity and to characterize some of its immuno-biochemical properties. The Syzyzium cumini was chosen to characterize SO as it showed maximum enzyme activity in the crude extract as compared to other plants. Absorption spectra of SO revealed two peaks at 235 and 277 nm, but no distinct peak in the visible region could be observed. Crude extract of all the plants were taken into considerations for immuno-biochemical studies. Despite of significant protein structure-functional similarities between plant and animal SO, no cross-reactivity could be established between the two sources of SO. These data suggested that plants SO, however, differed with regards to their immuno-biochemical properties.

Page(s): 83-86

Wheat (Triticum aestivum) peptide (s) mimic gibberellin action and regulate stomatal opening

Title: Wheat (Triticum aestivum) peptide (s) mimic gibberellin action and regulate stomatal opening

Authors: Ghosh, Amitava; Mandal, Palash; Sircar, Prasanta Kumar

Abstract: Wheat peptides (0.5 to 3 KDa M_r) mimick hormonal activity like that of gibberellins and forced open dark closed stomata. The deionized amphoteric peptides solution after passing through cation and anion exchanger resins was run through Amicon’s ultrafilters, 10, 3 and 0.5 kDa (M_r) cut off system. The 3 to 0.5 kDa fraction passed through sephadex LH-20 column and collected in 140 tubes (5 ml in each tube). The two fractions F 9 (91-100 tubes) and F 12 (121-130) were found much active on stomatal opening and -amylase activity, respectively and were ninhydrin positive. Capillary electrophoresis of F 9 fraction yielded several peptides ranging 1600 to 2200 (M_r) and F 12 fraction showed 1800 – 2800(M_r). Both the fractions were totally hydrolysed for amino acid analysis by HPLC. Most of the amino acids were present except cystein in both the fractions. The F 9 fraction, (peptide present in 10 μg fresh wt tissue per ml) induced the dark grown closed stomata to open upto 70%. In F 12 fraction, (peptide present in 10 μg fresh wt equivalent tissue per ml) showed -amylase induction which was much higher than GA₃(10^{-9 M}). The peptide might be present in membrane and bound with GA that activated -amylase m-RNA synthesis. The peptide might act directly on -amylase gene.

Page(s): 77-82

Production of bioemulsifier by Acinetobacter species isolated from healthy human skin

Title: Production of bioemulsifier by Acinetobacter species isolated from healthy human skin

Authors: Jagtap, Shweta; Yavankar, Supriya; Pardesi, Karishma; Chopade, Balu

Abstract: Six Acinetobacter sp. isolated from healthy human skin were checked for the production of bioemulsifier. Optimization studies indicated that Luria Bertani broth pH 7 supplemented with calcium chloride (1%) was the optimum medium. Temperature at 37°C was optimum and inducer oils in the medium did not enhance bioemulsifier production. Partial purification of bioemulsifier and chemical analysis revealed that it is a proteoglycan with protein (53%), polysaccharide (43%) and lipid (2%). Maximum emulsification activity obtained was 400 EU/ml. Thin layer chromatography revealed the presence of mannose and rhamnose sugar and oleic and palmitic acids as parts of lipids. The yield obtained was 1.9 g / l. Reconstitution studies revealed that the protein and polysaccharide fractions together display 94.55% of emulsification activity. It was also noted that the bioemulsifier was stable for 72 hr at 37°C and displayed good cleaning property towards different oils. The partially purified bioemulsifier formed stable oil-in-water emulsions with plant oils.

Page(s): 70-76

Role of glucagon-like peptide-1 in vascular endothelial dysfunction

Title: Role of glucagon-like peptide-1 in vascular endothelial dysfunction

Authors: Goyal, Sandeep; Kumar, Suresh; Bijjem, Krishnareddy V; Singh, Manjeet

Abstract: The present study has been undertaken to investigate the effect of exendin-4 (a glucagon-like peptide-1 agonist) in diabetes mellitus (DM) and hyperhomocysteinemia (HHcy)-induced vascular endothelial dysfunction (VED). Streptozotocin (55 mg kg⁻¹, iv, once) and methionine (1.7% w/w, po, 4 weeks) were administered to rats to produce DM (serum glucose >200 mg dl⁻¹) and HHcy (serum homocysteine >10 μM) respectively. VED was assessed using isolated aortic ring preparation, microscopy of thoracic aorta, and serum nitrite/nitrate concentration. Serum TBARS concentration was estimated to assess oxidative stress. Atorvastatin has been employed as standard agent. Exendin-4 (1 μg kg⁻¹, ip) and atorvastatin (30 mg kg⁻¹, po) treatments significantly attenuated increase in serum glucose and homocysteine but their concentrations remained markedly higher than sham control value. Exendin-4 and atorvastatin treatments markedly prevented DM and HHcy-induced (i) attenuation of acetylcholine-induced endothelium-dependent relaxation, (ii) impairment of vascular endothelial lining, (iii) decrease in serum nitrite/nitrate concentration, and (iv) increase in serum TBARS. However, this ameliorative effect of exendin-4 has been prevented by L-NAME (25 mg kg^-1, ip), an inhibitor of NOS. It may be concluded that exendin-4 may activate eNOS due to activation of GLP-1 and consequently reduce oxidative stress to improve vascular endothelial dysfunction.

Page(s): 61-69